Thermoformable materials have been used in association with medical structures such as casts, splints, orthotics, etc., for medical purposes for several years. Indeed, such materials offer several benefits over conventional non-thermoformable materials such as faster set times, eliminating the lengthy application process associated therewith and the dampness inflicted on the patients skin.
U.S. Pat. No. 4,778,717 is directed to a specific structure for a thermoplastic, thermoformable composite.
U.S. Pat. No. 5,652,053 discloses utilizing a molecular or intermolecular combination of materials comprised of an inter-penetrating polymer network so as to cause the combined structure to transfer from an amorphous state to a viscoelastic and rubbery state. While such a structure may provide some support to a user, it is not effective when a ridged support is desired such as is typically the case with a splint, cast, orthotic or exoskeleton.
U.S. Pat App. Nos. 20080319362 and 20120101417 both disclose a thermoformable cast or splint that can be used in association with an exothermic heating reaction for causing a thermoplastic material to go from a relatively rigid state to a malleable state so that the material can be formed to a portion of a patient in need of support. Unfortunately, in order to heat the thermoplastic material in such a reaction, the material is placed in a separate and distinct heating bag where the exothermic reaction takes place. After appropriate heating, the thermoplastic material is removed from the bag and ready for use.
In addition, the assignee of the present invention has provided oxygen-based heaters and various packages for same. See, e.g., U.S. Pat. No. 7,722,782, issued on May 25, 2010; U.S. application Ser. No. 12/376,927, filed on Feb. 9, 2009; U.S. application Ser. No. 12/874,338, filed on Sep. 2, 2010; U.S. application Ser. No. 14/055,250 filed on Oct. 16, 2013; U.S. application Ser. No. 14/058,719, filed on Oct. 21, 2013; U.S. application Ser. No. 14/058,496, filed on Oct. 21, 2013; and, U.S. Ser. No. 13/734,594, filed Jan. 4, 2013, all of which are incorporated herein by reference.
These disclosed heaters and packages are successful at providing an oxygen based heater and/or package for same.
While the above disclosed devices and methods may be capable of providing effective formable medical structures, none of them disclose such a device that provides for the conversion of a thermoformable material from a relatively rigid state to a formable state over a narrow temperature range, and, which reverts back to a clinically rigid state within a relatively short period of time, and, which remains in that state even at elevated ambient temperatures. The present invention is provided to solve these and other problems.